The play was ruled correctly. It was a fumble. Rules allow for a clear recovery after a whistle but they don’t get the return to the end zone.
It was recovered within a second or two of it hitting the ground. Read the rule. It is not referencing time frame but the action. Recovered in the immediate continuing football action.
Wrong wrong wrong. Yes, the rules allow for recovery after the ball is blown dead, if there is clear recovery in the "immediate continuing action". It is most certainly referencing time frame, what else could it be referencing? There is literally no definition of the word "immediate" that could be being used here that would make any sense other than a time frame.
immediate
adjective
1 occurring or accomplished without delay; instant:
an immediate reply.
2 following or preceding without a lapse of time:
the immediate future.
3 having no object or space intervening; nearest or next:
in the immediate vicinity.
Those are the only 3 definitions of the word that would even make sense here, and even the 3rd one is a stretch to say that would be being referenced in the use of "immediate" in the rule. Even if the third definition was being referenced, considering the ball rolled a good 10+ yards from where it was initially blown dead before anyone picked it up, you couldn't even argue that was correct. When you start to get into questioning the only logical definitions of a key word in a rule to try and absolve the refs of screwing up, you're trying too hard.
I've already stated it before, but if the Illinois player who nearly intercepted the ball had then immediately dove on top of it once it went through his hands and hit the ground, that would certainly count in the definition and you could easily say Illinois ball. If the other Illinois defender who was running over toward the guy who nearly intercepted the ball had dove on top of it after it fell to the ground, you could again argue that would count in the "immediate continuing action". Neither of those things happened, both of those players, after the ball touched the ground and the refs blew their whistles and signaled incomplete, turned and walked away from the ball, as did multiple other players.
Another thing that I haven't seen brought up yet, but is a perfect example of why you can't give the ball after that much had passed from it being blown dead. I hadn't noticed this previously, because I was only going off memory of what I saw when the play initially happened, I hadn't rewatched it yet. After the Illinois player drops the ball to the turf, and it starts to roll away, it rolls almost directly toward Jack Stoll who was running toward the play, possibly to make a tackle on the interception. Watch the play, Jack Stoll actually has a perfect opportunity to scoop the ball up, and if you watch from the one sideline angle they show, you can even see him start to square up to go after the ball, and then he stops and starts to just walk toward the huddle. Why does he stop? Because it's about that point the refs start to blow the whistle to signal incomplete. You can see the play I'm referencing in the gif below.
At the start, Jack Stoll is at the very left of the frame and the ball is behind the Illinois defender. You can see the ball bounce up and Jack Stoll moves in; you see him kinda widen his arms and lean forward like he's preparing to dive on the ball. The video cuts away right after this ends, but from another angle shown later, you can see he would have had very good shot at the ball, but after initially squaring up to go after it, he stops and turns back to the huddle, when the whistle blows. The stuff seen in this clip is the "immediate continuing action". If the Illinois defender on the ground would have crawled forward and grabbed the ball; or the defender behind him starting to celebrate what he thinks is an INT would have dove on the ball; or #55 would have immediately dove on the ball, that would count as the "immediate continuing action" and give Illinois the ball.
But, as you can see, Nebraska lost an opportunity to recover the ball as well, because of the whistle blowing, and the ball rolled around for a good 4-5 seconds before being picked up. You said it was recovered within a second or two from hitting the ground, that's not even remotely close. I paused the YouTube video when the ball hit the ground, and then counted from there to when it was picked up, which you can't even see because the camera cuts away, so I had to kind of guess. It's in the neighborhood of 4-5 seconds, maybe slightly longer since you don't actually see them pick the ball up, from when it hits the ground; and roughly 3-4 seconds from when you hear the whistle blow, which is probably delayed a little on the TV broadcast. That is not the "immediate continuing action" the refs got it WRONG.